Kate Miller-Heidke is a fresh new voice from Down Under

Saed Hindash/The Star-LedgerSinger-songwriter Kate Miller-Heidke, who is famous in Australia but little known here, performs Wednesday night at Le Poisson Rouge in New York.

NEW YORK — Even pop-savvy Americans don’t know much about her. They ought to get wise.

In her native Australia, Kate Miller-Heidke is a star — the rare celebrity worth celebrating. She’d already established herself as one of Brisbane’s favorite performers — one who ditched a career in opera to apply her vocal talents to her quirky, personal songs — when “The Last Day on Earth,” her latest single, topped the charts Down Under. Emboldened by that success, she decided to try her luck in the States.

Wednesday’s show at the intimate Le Poisson Rouge was the last of a 20-date American swing. Soon she’ll be heading back to Queensland, where she’ll play at houses considerably bigger than this one. The room was crammed: fans, curiosity-seekers and Australiaphiles gathered to laugh at her jokes, marvel at her acrobatic vocals, and cheer her frequent departures from pop convention. In her Aussie accent, the engaging Miller-Heidke thanked the audience for the warm reception.

Let’s hope she was sincere, and that she’ll hurry back soon. American pop desperately needs personalities as offbeat as hers.

Miller-Heidke incorporates opera techniques into her performances, but not always in the manner that audiences might expect. On the plain-spoken “Politics in Space,” she ended each chorus with a sudden operatic flourish. “Dreams” featured a high-held note that would have been the envy of the sopranos at the Met — until she began to inhale rather than exhale, producing a sound not unlike that of a deflating balloon. Late in the set, she sang “Psycho Killer” in full-blown operatic style, reclaiming some of the drama and horror that overexposure has driven out of the Talking Heads classic.

The crowd didn’t always know how to receive these irruptions. Was this parody, tribute, psychotic bravery or something else?

Miller-Heidke, who sparkles with mischievous intelligence, probably just wanted to keep listeners on their toes. She can coax a remarkable range of sounds out of her throat: On “Words,” she slid rapidly between notes with the electronic precision of a Moog synthesizer. The tracks on “Curiouser,” her sophomore album, are awash in tics, hiccups, vertiginous swoops and vocal tones that dissolve into the mixes like sugar stirred into a cup of coffee. Onstage, she even broke out a devil’s voice.

But it would be wrong to imply that Miller-Heidke favors sound over substance. She’s a storyteller at heart, frequently humorous and reliably insightful. She can also be talky: “Caught in the Crowd,” an apology to a bullied classmate who the narrator didn’t have the pluck to stand up for, is as conversational as Mike Skinner’s half-sung work with the Streets. She saves her ornamentation for the margins; when she’s got a gag to deliver, she usually does so in a voice that’s sweet, polite and slightly guarded.

“If you’re God’s gift to women,” she sang to an unctuous suitor on Wednesday, “then God got it wrong, yes, She got it wrong.” (The audience roared.)

Occasionally, Miller-Heidke’s sense of humor runs away with her. Her songs about Facebook and “Australian Idol” are more Tom Lehrer than Cyndi Lauper; from time to time, the show dipped dangerously toward cabaret. She is saved from the novelty bin by guitarist and principal collaborator Keir Nuttall, who blows away any such concerns through the sheer force of his talent. Nuttall is an outstanding acoustic guitar player, able to switch gracefully between heavy power chords, fast riffing and soft, insistent bass-string patterns. The guitarist — who, unsurprisingly, also plays in a Brisbane-based prog-rock band — can get extremely quiet and still carry the backbeat without a percussionist’s assistance.

Nuttall layered “Curiouser” with springy electric guitar and all the burbling and whirring synthesizers he could get his hands on. But at Le Poisson Rouge, Miller-Heidke and Nuttall appeared as a duo. Songs that, on the album, are saturated with instruments and backing vocals were, in concert, stripped to bare essentials: voice, acoustic, occasional piano and a bit of tambourine. “Can’t Shake It,” a dance song about the singer’s inability to dance, was transformed from a pounding piece of neo-new-wave to a spare, sinister art-folk stunner. It was the high point of an arresting concert — one notable for its bravery as well as its musical excellence.